Retrospectively assessed physical work environment during working life and risk of sickness absence and labour market exit among older workers.

OBJECTIVE: To determine the prospective association between retrospectively assessed physical work environment during working life and prospectively assessed sickness absence and labour market exit among older workers. METHODS: Using Cox regression analyses we estimated the 4-year to 6-year prospective risk of register-based long-term sickness absence (LTSA), disability pension, early retirement and unemployment from exposure to different physical work environmental factors during working life among 5076 older workers (age 49-63 at baseline) from the Copenhagen Aging and Midlife Biobank cohort. RESULTS: Very hard physical work throughout working life was a risk factor for LTSA (HR 1.66,95% CI 1.32 to 2.07), disability pension (HR 2.21,95% CI 1.04 to 4.72) and early retirement (HR 1.57,95% CI 1.13 to 2.17). Both short-term (<10 years) and long-term (≥20 years) exposures to lifting or carrying of heavy burdens predicted the risk of LTSA (HRs 1.49-1.56) and disability pension (HRs 2.26-3.29). In contrast, exposure to dust was associated with LTSA and disability pension only following 20 or more exposure years. CONCLUSIONS: Retrospectively assessed hard physical work during working life and exposure to several factors in the physical work environment, especially heavy lifting, were important for labour market exit and sickness absence. This study underscores the importance of reducing physical work exposures throughout the working life course for preventing sickness absence and premature exit from the labour market.

Retrospectively assessed psychosocial working conditions as predictors of prospectively assessed sickness absence and disability pension among older workers.

BACKGROUND: The aim was to explore the association between retrospectively assessed psychosocial working conditions during working life and prospectively assessed risk of sickness absence and disability pension among older workers. METHODS: The prospective risk of register-based long-term sickness absence (LTSA) and disability pension was estimated from exposure to 12 different psychosocial work characteristics during working life among 5076 older workers from the CAMB cohort (Copenhagen Aging and Midlife Biobank). Analyses were censored for competing events and adjusted for age, gender, physical work environment, lifestyle, education, and prior LTSA. RESULTS: LTSA was predicted by high levels of cognitive demands (HR 1.31 (95% CI 1.10-1.56)), high levels of emotional demands (HR 1.26 (95% CI 1.07-1.48)), low levels of influence at work (HR 1.30 (95% CI 1.03-1.64)), and high levels of role conflicts (HR 1.34 (95% CI 1.09-1.65)). Disability pension was predicted by low levels of influence at work (HR 2.73 (95% CI 1.49-5.00)) and low levels of recognition from management (HR 2.04 (95% CI 1.14-3.67)). CONCLUSIONS: This exploratory study found that retrospectively assessed high cognitive demands, high and medium emotional demands, low influence at work, low recognition from management, medium role clarity, and high role conflicts predicted LTSA and/or disability pension.

Influence of physical and psychosocial work environment throughout life and physical and cognitive capacity in midlife on labor market attachment among older workers: study protocol for a prospective cohort study.

BACKGROUND: As average life span increases, elderly will account for an increasing proportion of the total population in most parts of the world. Thus, initiatives to retain older workers at the labor market are becoming increasingly important. This study will investigate the influence of physical and psychosocial work environment throughout working life and physical and cognitive capacity in midlife on labor market attachment among older workers. METHODS/DESIGN: Approximately 5000 participants (aged 50-60 years) from the Copenhagen Aging and Midlife Biobank (CAMB) will be followed prospectively in a national register (DREAM), containing information on a week-to-week basis about social transfer payments for about 5 million Danish residents. Using Cox regression, we will model the risk of long-term sickness absence, disability pension, early retirement and unemployment within a 4 to 6 year period from the baseline measurement as a function of the following predictors: 1) physical work demands throughout working life, 2) psychosocial working conditions throughout working life, 3) physical capacity in midlife, 4) cognitive capacity in midlife. Estimates will be adjusted for age, sex, lifestyle, socioeconomic position, chronic disease and long-term sickness absence prior to baseline. DISCUSSION: The project will generate new knowledge on risk factors for loss of labor market attachment. The results will potentially contribute in identifying factors that could be targeted in future interventions for maintaining a longer and healthier working life among older workers.

Distribution of subjective health complaints, and their association with register based sickness absence in the Danish working population.

AIMS: To describe the distribution of subjective health complaints (SHCs) in a Danish working population and the associations between SHC and register based sickness absence. METHODS: The study entailed 2876 men and 3574 women aged 18-59 years that constituted the 2005 panel in the Danish Work Environment Cohort Study (DWECS). All had completed a subjective health complaints inventory and the Nordic Musculoskeletal Questionnaire (NMQ). Seven SHC/NMQ indices were constructed and merged with subsequently collected data on prolonged sickness absence periods (each period > 14 days) that was registered in the national Danish register on social transfer payments: the DREAM register. Ordinal logistic regression was used to model the cumulative odds for sickness absence as a function of strata. RESULTS: The majority of participants reported at least one SHC during a 30-day period (circa 89% of the men and 95% of the women). The reports of severe SHC, defined as recurring SHC within the 30-day period, were less common. About 55% of the men and 68% of the women reported at least one severe SHC during a 30-day period. The odds ratios of sickness absence increased with the number of SHC a participant acknowledged. The odds ratios were slightly reduced after adjusting for age, disease history and social class. CONCLUSIONS: The majority of the working population in Denmark report at least one SHC during a 30-day period. Roughly half of the population report having at least one recurrent (often to very often) SHC during the last 30-days (severe SHC). Reporting the presence of several SHCs increases the likelihood of having more prospectively registered periods of sickness absence above two weeks.

Influence of self-efficacy on compliance to workplace exercise.

BACKGROUND: Continuous neck and shoulder pain is a common musculoskeletal complaint. Physical exercise can reduce pain symptoms, but compliance to exercise is a challenge. Exercise-specific self-efficacy has been found to be a predictor of participation in preplanned exercise. Little is known about the influence of exercise-specific self-efficacy on compliance to workplace physical exercise. PURPOSE: To determine the influence of exercise-specific self-efficacy on compliance to specific strength exercises during working hours for laboratory technicians. METHODS: We performed a cluster-randomized controlled trial, including laboratory technicians from two industrial production units in Copenhagen, Denmark. The participants were randomized to supervised specific strength exercises for the neck and shoulder muscles for 20 minutes three times a week (n = 282) or to a reference group (n = 255). The participants answered baseline and follow-up questions regarding self-efficacy and registered all exercises in a diary. RESULTS: Overall compliance to exercises was 45 %. Compliance in company A (private sector) differed significantly between the three self-efficacy groups after 20 weeks. The odds ratio of compliance was 2.37 for moderate versus low self-efficacy, and 2.93 for high versus low self-efficacy. No significant difference was found in company B (public sector) or in the intervention group as a whole. CONCLUSION: We did not find self-efficacy to be a general statistically significant predictor of compliance to exercises during 20 weeks, but found self-efficacy to be a predictor of compliance in a private sector setting. Workplace-specific differences might be present and should be taken into account.

Physical capability in midlife and risk of disability pension and long-term sickness absence: prospective cohort study with register follow-up.

Objective The aim of this study was to determine the association of physical capability with health-related labor market outcomes among older workers. Methods The prospective risk of disability pension and long-term sickness absence (LTSA) of ≥6 weeks was estimated from physical capability on 5076 older workers (age 49-63 years) from the Copenhagen Aging and Midlife Biobank (CAMB). Physical capability was objectively measured through nine different tests (jump performance, postural balance, chair-rise, explosive muscle strength, maximal strength of the hand, back and abdominal muscles, lung capacity, and aerobic fitness) and linked to a high-quality register on social transfer payments among all Danish residents. Cox-regression analyses estimated the association of physical capability with risk of disability pension and LTSA. Results For all measures, low physical capability [≥1 standard deviation (SD) below the mean for each gender] was associated with increased risk of disability pension and/or LTSA, whereas high physical capability (≥1 SD above the mean for each gender) was not. A capability-response association was observed between the number of tests with low capability and disability pension and LTSA (P<0.0001) - with the risk-estimate for disability pension being 8.52 (95% confidence interval 3.98-18.25) when low capability was present in ≥5 physical tests. Population attributable risks analyses indicate that 42% of the disability pension cases were attributable to low physical capability whereas this was the case for 12% of the LTSA cases. Conclusions Using objective measures of predictors and outcomes, our study shows that low physical capability in midlife was associated with increased risk of disability pension and LTSA. The results indicate that increasing physical capability to an average level among older workers with low capability could potentially contribute to preventing >40% of premature exits from the labor market.

Content and quality of workplace guidelines developed to prevent mental health problems: results from a systematic review.

Objectives A wide range of guidelines have been developed to prevent work-related mental health problems (MHP), but little is known about the quality of such guidelines. We systematically reviewed the content and quality of workplace guidelines aiming to prevent, detect, and/or manage work-related MHP. Methods We conducted systematic online and database searches (MEDLINE; Web of Science; PsychNET; occupational safety and health databases) to identify guidelines. Eligibility criteria included guidelines recommending primary, secondary, or tertiary preventive interventions to be implemented at the workplace by employers, employees or organizational staff. A minimum of minimum three independent reviewers assessed the quality of guidelines using the Guidelines for Research and Evaluation (AGREE II). Guidelines rated ≥65% with regards to domain I, II, and III were considered to be of good developmental quality. Results Seventeen guidelines were quality assessed. Guidelines mainly targeted employers: eight guidelines recommended primary preventive interventions (eg, reduction of psychosocial hazards by risk management procedures), three recommended tertiary (eg, stay at work or return to work procedures for management), and six recommended a combination of primary, secondary and tertiary interventions (eg, facilitate return to work by increasing mental health literacy of all staff and coordination of sick-listed employees). Four guidelines had developed recommendations of good quality, but the evidence of two guidelines was outdated and studies documenting the effect of implementation were not yet available. Conclusions Few guidelines have been developed with sufficient rigor to help employers prevent or manage work-related MHP and evidence of their effectiveness remains scarce.

Cumulative occupational mechanical exposures during working life and risk of sickness absence and disability pension: prospective cohort study.

Objectives The aim of this study was to determine the prospective association of cumulative mechanical exposure during working life with health-related labor market outcomes. Methods This prospective cohort study combines data from 5076 older workers (age 49-63 years) from the Copenhagen Aging and Midlife Biobank with a job exposure matrix and a national register containing information on social transfer payment. By coding individual job histories from the Danish version of ISCO-codes (International Standard Classification of Occupations), we calculated cumulative occupational mechanical exposures from a JEM for ton-years (lifting 1000 kg each day in one year), lifting-years (lifting loads weighing ≥20 kg >10 times each day in one year), kneeling-years (kneeling for one hour each day in one year) and vibration-years (whole-body vibration for one hour each day in one year). Cox-regression analyses estimated the relative risk of register-based long-term sickness absence (LTSA) and disability pension with cumulative occupational mechanical exposures throughout working life. Analyses were censored for competing events and adjusted for multiple confounders. Results During the follow-up period, 970 persons (19.3%) had ≥1 episode of LTSA and 85 persons (1.7%) were granted a disability pension. Number of ton-, lifting- and kneeling-years showed an exposure-response association with increased risk of LTSA (P<0.0001). In addition, both long term [≥20 years; hazard ratio (HR) 1.76 95% CI 1.39-2.22] and short term (<10 years; HR 1.20 95% CI 1.02-1.41) exposure to kneeling work increased the risk of LTSA. Lifting-years, but not the other mechanical exposures, were associated with risk of disability pension (HR 1.75 95% CI 1.01-3.04). Conclusions Cumulative occupational mechanical exposures during working life - such as lifting and kneeling work - increased the risk of LTSA. Importantly, being exposed to lifting increased the risk of disability pension.

Development of sensitisation or tolerance following repeated OVA inhalation in BALB/cJ mice. Dose-dependency and modulation by the Al(OH)3 adjuvant.

Anthropogenically induced exposures may, due to their adjuvant effect, promote development of sensitisation to commonly occurring aeroallergens. No generally accepted model exists for determination of adjuvant effect of airborne substances. Therefore, BALB/cJ mice were exposed for 10 consecutive days with ovalbumin (OVA) solution, 25 mg/l-10 g/l (0.0025-1%) for 20 min/day, with and without the Al(OH)(3) adjuvant (0.5%). Four days after the last aerosol exposure, no OVA specific IgE and only low IgG1 were produced. Subsequent parenteral OVA administration showed that the 10 g/l solution induced full tolerance of the IgE response, whereas only partial tolerance was apparent with 25 mg/l OVA. The Al(OH)(3) adjuvant counteracted development of tolerance that was fully prevented at the 25 mg/l OVA concentration. Development of IgG1 was increased in a concentration-dependent manner with 500 mg/l-10 g/l OVA. No increase occurred at the 25 mg/l level, but addition of Al(OH)(3) increased IgG1 production to the same level as the higher OVA concentrations. Concentrations from 1.25 mg/l to 10 g/l OVA were studied with ten exposures followed by once-weekly aerosol exposure for uptil 6 weeks. In the range from 1.25 mg/l to 10 g/l, IgE production was time- and concentration-dependent. Both the IgE and IgG1 production were markedly promoted by Al(OH)(3). However, with aerosol exposures, the IgE antibody productions were not sufficient to increase the level of inflammatory cells in broncho-alveolar lavage fluid. Overall, this study showed that airborne Al(OH)(3) was able to counteract tolerance and increase specific IgE and IgG1 production.

Work environment and somatic hospital admissions in Denmark 1994-1999.

OBJECTIVE: The aim was to elucidate the usefulness of the excess hospitalisation fraction (EHF) approach-as a practical alternative to the calculation of etiological fractions-for prioritising national preventive measures in the total environment. In this study we used the inequality in somatic hospitalisation across industrial sectors as an example. The presented EHFs may provide an estimate of the order of magnitude of the prevention potential, which may also be useful in priority setting in countries comparable to Denmark. METHODS: All economically active adults in Denmark were followed-up for 6 years after hospital discharge, and industrial specific EHFs for 58 industrial sectors were calculated for 11 main diagnostic groups. Assuming 'education and research' to be the industrial sector which is least exposed to occupational hazards, we calculated the EHFs as a practical approximation to the etiologic fraction for all other industries, using hospitalisation rates adjusted for age. In addition, we also controlled for social class since many risk factors may also be related to life style or living conditions. RESULTS: Compared to 'education and research' the EHF in all other industries was (additional control for social class in brackets): Women 11% (7%), men 15% (8%). The EHFs for some of the main diagnostic groups were as follows: Circulatory diseases: Women 18% (12%), men 16% (10%). Neoplasms: Women 3% (4%), men 8% (6%). Musculoskeletal diseases: Women 19% (12%), men 21% (10%). Diseases in the respiratory system: Women 12% (8%), men 16% (9%). Diseases in the nervous system: Women 12% (7%), men 17% (12%). Violent events (injuries and trauma): Women 6% (5%), men 17% (6%). CONCLUSIONS: The advantage of this method is that the EHF can be calculated for all diseases and for the whole population without detailed knowledge of causal risk factors and their distribution in the population. Two main methodological problems are that we cannot control for selection bias related to occupation, and that the control for social class may lead to conservative estimates. Our estimates are, however, close to estimates of etiologic fractions published in the literature. Large unexpected EHFs for diseases of the blood and blood-forming organs should be seen as challenges for future research.

Interleukin-8 secretion from monocytic cell lines for evaluation of the inflammatory potential of organic dust.

The potential of organic dust to induce inflammation in vitro can be viewed as a crude measure of the total biologically active compounds in a dust sample. The purpose of this study was to further develop an in vitro screening method for evaluation of potential hazard related to low doses of dust exposure using two monocytic cell lines (U937 and THP-1). Dust was obtained from schools in Copenhagen. U937 and THP-1 cells were stimulated with dust for 24 h and interleukin-8 secretion was measured. The initial slopes of the dose-response curves were used to calculate the inflammatory potential, or potency factor (PF), of the samples. In characterization of the method, lipopolysaccharide from Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Salmonella enteritidis were tested together with three glucans, nickel sulfate (NiSO(4)), methyl methacrylate (MMA), formaldehyde, and four surfactants. The PF values of LPSs in both monocytic assays ranked as follows: S. enteritidis> E. coli>K. pneumoniae/P. aeruginosa. The PF values of NiSO(4), MMA, formaldehyde, and the surfactants were zero or below. Using the THP-1 cell line, the PF values of dust samples were 30 times higher than when using the U937 cell line, and 7 times higher than when using the lung epithelial cell line (A549). The high sensitivity of the THP-1 bioassay makes it potentially useful as a screening tool for hazard evaluation of dust from, e.g., the indoor environment.